Writing instrument with retractable point



1956 w. WlCHMANN WRITING INSTRUMENT WITH RETRA CTABLE POINT Filed March4, 1955 7 z N. 1 Mm .1 w

INVENTOR W/LHEZM WICHMANN ATTORNEY fFIGJ.

United States Patent Oflice 2,757,639 Patented Aug. 7, 1956 WRITINGINSTRUMENT WITH RETRACTABLE POINT Wilhelm Wichmann, Clifton, N. J.

Application March 4, 1955, Serial'No. 492,083

3 Claims. (Cl. 12042;03)

This invention relates to writing implements-more particularly toretractable pens and pencils.

In conventional instruments of this category having a longitudinallymovable stem or other support for a writing point, mechanisms areemployed which are manually manipulated to cause a positive operativeprojection or retraction of the point. Aside from the fact that positivemanipulative efforts are required to be performed upon special actuatingelements, the mechanisms employed are necessarily intricate, requirecareful and skillful assembling operations and are correspondinglycostly to produce.

It is primarily within the contemplation of my invention to provide aconstruction of writing instrument with a minimum of components, and inwhich the use of manually manipulated elements for projecting andretracting the writing point is eliminated. And in this aspect of myinvention it is my objective to enable the point projecting andretracting operations to be performed merely by reversing the positionof the instrument from the operative writing position to the retractedposition, and vice versa.

Another object of my invention is to enable the writing point to be heldlocked in its writing position without manipulating any locking element,but merely by holding the instrument in its normal writing position.

A further object of this invention is to provide a structure withreadily fabricated parts, and that can be readily assembled without theuse of skilled labor, or special tools or jigs.

Other objects, features and advantages will appear from the drawings andthe description hereinafter given.

In the drawings,

Figure 1 is an enlarged longitudinal sectional view of an embodiment ofmy invention, the illustrated pen being shown in its operative writingposition.

Figure 2 is a part-sectional, part-elevational view of the device ofFigure 1, shown inverted, in its retracted inoperative position.

Figure 3 is an exploded fragmentary view of the components of the deviceof Figure 2. 1

Figure 4 is an enlarged longitudinal sectional view of anotherembodiment of my invention, shown in its operative writing position.

Figure 5 is a view substantially like Figure 4 but showing the deviceinverted, in its retracted inoperative position.

In the form of my invention illustrated in Figures 1 to 3, the rearouter casing 10 is force-fitted over the centrally-aperturedpoint-carrier guide member 11, the latter having a forwardly extendingboss 12 with the externally threaded portion 13 extending into and inthreaded engagement with the internally threaded wall 14 of the centralcavity 15 of the generally cylindrical connector 16, the latterextending into the rear end of the forward casing 17. In the embodimentshown, said con-.

12, the intermediate thickened portion 19 being porportioned to extendbetween the ends20 and21 of the respective casings 10 and 17. Theinternal passageway 22 of said guide 11 communicates with the passageway23 of connector 16, said passageway being proportioned to accommodatethe cartridge stem 24 and permit the latters longitudinal movementrelative to said casings 10 and 17.

The front portion 25 of casing 17 contains therein the axial aperture26, proportioned to permit the longitudinal movement therethrough of theelongated writing tip 27, carried by said stem 24, during the lattersoperative movement to be hereinafter describedwhereby.said tip may beoperatively moved from its writing position of Fig. 1 to its retractedposition of Fig. 2.

The rear portion 28 of said rearcasing 10 contains the hollow sleeve 29fixedly supported in place, said sleeve having an open-ended passageway30 communicating with the rear well 31 of casing 10 and the somewhatlarger open-ended passageway 32. The relative proportions of passageways30 and 32 are such that a narrow annular shoulder 33 is formedtherebetween, the annular internal edge portion 34 of which serves theimportant function of a jamming ridge to hold said stem 24 in itsforward limiting position and said tip 27 in its projected writingposition, as will more clearly hereinafter appear.

Disposed between and in abutting engagement with the opposing ends 35and 36 of said sleeve 29 and guide 11, respectively, is the hollowcylindrical spacer 37, the central passageway 38 of which is incommunication with passageway 32 and the interior chamber 39 of theforward casing 17. The said stem 24 is proportioned for longitudinalmovement through said passageway 38, as well as through said otherpassageways, so that it may freely moveupon a change of the instrumentspositions between that of Figure 1 and that of Figure 2-to said stemstwo limiting positions. In the operative position (Fig. 1), the frontcollar 40 is in abutment with the front wall 41; and in the inoperativeor retracted position (Fig. 2), the tip portion 27 is completelycontained within the casing; while the rear portion 42 of stem 24 isdisposed'within the passageway 30. Said rear portion is provided with arear stop'member which, in the form being described, is separable fromthe stem. The form of stop member illustrated is ball 43 upon which therear portion of the stem is resting, in retracted position, the ball inturn resting upon jamming pin 44 supported within well 31.

The said ball 43 is proportioned for entry within passageway 30 when thepen is inverted, as shown in Fig. 2; and when the pen is in itsoperative position shown in Fig. 1, the ball is supported by the rearend portion 42 of hollow stem 24. In said latter position, the ball isspaced from the annular edge portion or ridge 34, to provide an opening45 for partial entry of said jamming pin 44, in'a manner to behereinafter described. 1

Said jamming pin 44 comprises a substantially conical head 46, itsmaximum width being at rear portion 47-- said portion curving rearwardlyand inwardly to join the narrow neck 48 connected to the rear bodyportion 49the latter being preferably of elongated configuration and ofgreater weight than said head 46. The width of said head at portion 47is greater than that of said opening 45 when the ball is disposed off atone side, against ridge portion 34a, as shown in Fig. 1. When said headis disposed in said opening 45, as illustrated in said latter figure, itis in engagement with ridge portion 34b and the ball 43, and stoppedfrom further entry through the said opening 45. The ball 43 and pin 44are thus jammed together against ridge 34, to hold stem 24 againstrearward movement. This is the operative one of the 3 two positions ofthe stemthe position in which the tip 27 is in its protruding writingposition.

Because of the jamming action above described, the stem isllnid lbcltedin its writing position; and operative writing pressure upon tips 2.7will not dislodge the stem and the tip from their operative position.

The operation of bringing the said pen components to their writingposition thus entails the simple step of inverting the pen from theinoperative position of Fig. 2 to that of Fig. 1. down until collarengages the wall 41, the ball 43 drops upon the rear end 42 of the stem,and the jamming pin 44 drops down until the head 46 reaches: the jammingposition above described. It should be noted that the length of pin- 44is sufficiently greater than. the diameter of passageway 30 to insureits remaining at all times with head 46 in the. foremost position. An itis also to be observed that the weight of rear body portion 49 serves togravitationally force the head 46 into said jamming. position.

To retract the tip 27, the pen is. brought to the position of: Fig. 2.The weighted body portion 49 will then cause the pin 44 to drop backfrom its jamming position into the well 31; and the ball. 43 and stem 24will correspondingly move downwardly to the retracted limiting positionillustrated-the relative proportions of the pin, ball and stem beingsuch that the tip 27 will be entirely contained within the casing 17-,as aforesaid.

Both operations are thus performed without the use of any manuallymanipulated locking and. releasable mechanisms which characterizeconventional retractable writing instruments. Moreover, the componentscan be readily assembled without the usual fitting operations andwithout the need to use special assembling jigs and tools. As can beseen from Fig. 3, the assembling operation of the rear portion simplyconsists of successively dropping in the pin 44. and ball 43,.insertingthe spacer 37 and pressing. the guide 11 into place. The front portionis assembled by pressing the connector 16 into place. Thereafter thecartridge stem- 24 is inserted. in the usual way, and the forward andrear portions screwed to.- gether.

The modified form of my invention illustrated in Figs. 4 and 5 containssubstantially the same components, except that in place of the ball 43 Iemploy the cam member 50 comprising the cylindrical body portion 51, therear inclincd cam surface 52 and the short bottom shaft 53 dis.- posedwithintthe hollow rear portion 42 of stem 24.

When the pen is turned to the operative position shown in Fig. 4,. thepin 44 drops-upon cam surface 52, the head 46 sliding down until it isengaged by the ridge 34, whereupon no further upward movement. ispossible. Hence the point carrying stem, is held locked in its operativewriting position. Upon, a reversal of the pen. to the position of Fig.-5, the pin 44 drops into well 31,. as in the first. case described, andthe cam member 50 slidably moves down until stoppedv by the pinthe stem:gravitationally moving down to its retracted position.

In the above description, the invention has been disclosed merely by wayof example and in preferred man- The stem 24 gravitationally slides ner;but obviously many variations and modifications may be made therein. Itis to be understood, therefore, that the invention is not limited to anyspecific form or manner of practicing same, except insofar as suchlimitations are specified in the appended claims.

I claim:

1. In a writing instrument, a hollow casing, an elongated. cartridgestem disposed within. said casing and operatively movable between twolimiting positions, one being a rear retracted inoperative position andthe other a forward operative writingposition, an apertured portion atthe forward end of the casing and communicating with the interiorthereof, said stem having at the front thereof, a terminal portion witha writing tip operatively movable through said apertured portion upon anoperative movement of said stem, said casing having an internal annularridge portion spaced forwardly from the rearmost portion of said casing,said ridge dividing said casing into a rear passageway and a relativelywider front passageway, a stop member at the rear of and movable withsaid stem, said stop member having a rear end surface generally inclinedtoward said ridge, a jamming member comprising a conical front endportion and a rear body portion connected therewith by means of a narrowneck. portion joining, the maximum width at the base of the headportion; to the rear body portion, said conicall front portion beingengageable with the inclined surface of said stop member to tilt thebody portion and move the head portion along said inclined rear endsurface by the free falling of said jamming member and the consequentdownward movement of the conical front end portion of said jammingmember below said ridge to define a jamming position with the stopmember bearing against said jamming member and both of said membersbearing against opposite sides of said ridge, and said stem being.loosely mounted within said casing whereby it is gravitationally movablebetween its said two limiting p0 sitions upon an operative movement ofsaid writing instrument between its vertical operative writing positionand an inverted: inoperative position.

2. In a writing instrument, the combination according to claim 1 whereinsaidstop member is a spherical member in engagement with the rear end ofsaid stem.

3. In a writing instrument, the combination according to claim 1 whereinsaid stop. member is provided with a substantially flat: inclined rearcam surface with which the head of said pin is in slidable engagement.

References Cited in the file of this patent UNITED STATES PATENTS501,850 Stuart July 18, 1893 2,587,935 Wallace Mar. 4, 1952 2,676,569Schrader Apr. 27, 1954 2,693,170 Sears Nov. 2, 1954 2,741,226 DietrichApr. 10, 1956 FOREIGN PATENTS 2,017 Great Britain 1890 427,530 ItalyNov. 20, 1947 428,388 Italy Dec. 16, 1947

